What is overall cardiovascular risk?

Overall cardiovascular risk refers to the probability, for a given person, of developing a major cardiovascular event — heart attack, stroke, or another complication linked to atherosclerosis — over a given period, generally the next 10 years. This is a different concept from simply having or not having a single isolated risk factor, and understanding it genuinely changes how you approach prevention.

What a “major cardiovascular event” actually covers

Behind this phrase lie several specific situations: heart attack (blockage of a coronary artery supplying the heart), stroke (whether ischemic, from a blockage, or hemorrhagic), and, to a lesser extent, other manifestations of atherosclerosis such as peripheral artery disease. These events share a common origin: the gradual buildup of atherosclerotic plaques on artery walls, a process that often begins decades before any symptom appears. It is precisely this long silent phase that makes assessing overall risk so useful — it allows action before this process reaches a critical stage.

A major issue in France, the United States, and worldwide

Cardiovascular disease is the leading cause of death worldwide: the World Health Organization (WHO) attributes about 18 million deaths a year to it, or nearly one death in three. More than three-quarters occur in low- or middle-income countries. In the United States, it is also the leading cause of death. In France, it causes about 140,000 deaths a year: the second leading cause of death after cancer, and the leading cause in women. Each year, France records about 80,000 heart attacks and more than 120,000 hospitalizations for stroke.

Cardiovascular mortality has, however, fallen a great deal over the past fifty years in wealthy countries, thanks to declining smoking rates, treatment of high blood pressure and cholesterol, and advances in emergency care. This decline shows that prevention works, and that's the whole point of assessing your own risk.

Why look at the whole picture rather than one factor at a time

A common misconception is that risk factors should be added up one by one to assess overall danger. In reality, cardiovascular risk factors don't add up — they multiply. Someone with both high blood pressure and a smoking habit doesn't simply have “twice as much” risk as someone with only one of these factors: the combined risk is markedly higher than the sum of the two risks taken separately.

Take a concrete, simplified example to illustrate this principle: if high blood pressure multiplies risk by 2 and smoking by 5, the combined risk in someone with both factors isn't “2+5=7” as additive logic would suggest, but closer to “2×5=10” under multiplicative logic — and often even more, because risk factors also interact with each other biologically, each one worsening the other's impact on the artery wall. The difference between these two results (7 versus 10) concretely illustrates why simple addition would underestimate real risk. This is exactly why tools like SCORE2 calculate an overall risk from several variables combined mathematically, rather than simply counting how many risk factors are present or adding them up one by one.

From Framingham to SCORE2: a story spanning several decades

Tools for calculating cardiovascular risk are nothing new. The first widely used model came from the Framingham Study, launched in 1948 in the United States: it has followed thousands of residents of a single Massachusetts town for decades, and it was in its publications from the 1960s that the phrase “risk factor” first appeared. This pioneering work made it possible to statistically identify the main cardiovascular risk factors as we know them today. Since then, models have been refined and adapted to European populations, giving rise to SCORE, and then to its updated version, SCORE2, in 2021, built from 45 European cohorts totaling nearly 700,000 people, then adjusted and validated on data from more than 10 million people — a degree of statistical validation that gives this tool markedly greater reliability than a simple empirical estimate.

An assessment reserved for people in “apparent good health”

Overall cardiovascular risk calculators like SCORE2 are specifically intended for people who have never had a cardiovascular event and who don't already have diabetes — in that case, risk is considered differently (dedicated tools exist, such as SCORE2-Diabetes, covered in another article on this blog). For these people in “apparent good health,” the goal of the calculation is to anticipate rather than react: identifying, before a problem occurs, who might benefit from stronger preventive care.

This restriction on who the tool applies to isn't trivial: someone who has already had a heart attack, for example, is automatically considered at very high risk of recurrence, with no need for a further calculation to establish that. Overall risk calculation therefore remains most valuable specifically for the period before a first event — the window where prevention adds the most value.

The variables taken into account

The SCORE2 score, the current European reference, relies on five variables: sex, age, systolic blood pressure, non-HDL cholesterol, and smoking status. These five elements, combined through a statistically validated equation, produce a numerical estimate of 10-year risk — far more precise than simply adding up present or absent factors. The choice of these five specific variables, rather than others, comes from decades of epidemiological research that identified those with the most robust and most reproducible predictive power from one population to another.

A calculation adapted to each region and each age

Cardiovascular risk isn't the same everywhere. SCORE2 therefore uses equations adjusted for four major regions of Europe, classified according to how common these diseases are. France belongs to the “low-risk” region. For people aged 70 and over, a specific version, SCORE2-OP, accounts for the fact that at this age, other causes of death compete with cardiovascular disease.

Outside Europe, other tools are used. In the United States, doctors calculate atherosclerotic cardiovascular disease risk (ASCVD) using equations from the American College of Cardiology and the American Heart Association, built from American cohorts. The WHO published risk charts adapted to 21 regions of the world in 2019, usable even without a blood test. This is why the Hygietest tool relies on SCORE2 and SCORE2-OP for Europe, and on the ASCVD equations for the United States.

What this is not

An overall cardiovascular risk score is not a certain prediction. The goal isn't to announce with certainty that an event will occur, but to identify people who could genuinely benefit from appropriate preventive measures — lifestyle changes, closer follow-up, or sometimes medication depending on the risk level obtained. Any result should always be interpreted as a statistical probability applied to a risk profile, not as a definitive individual verdict.

Continuously evolving calculation models

Cardiovascular risk calculators aren't set in stone: they are regularly revised as new population data becomes available, and as research refines our understanding of the mechanisms involved. SCORE2 itself replaced an earlier version (SCORE, developed in the 2000s), with significant methodological adjustments to better reflect changes in European populations and measurement practices. This ongoing evolution explains why cardiovascular risk calculation guidelines can shift slightly from one decade to the next, without this calling into question the validity of past assessments at the time they were made.

For a personalized estimate based on these same variables, see the “What's my cardiovascular risk?” test.